CHAPTER 17.04:  STORMWATER MANAGEMENT
Publisher's Note:This Chapter has been AMENDED by new legislation (Ord. O-202009-10-030, passed 9-15-2020). The text of the amendment will be incorporated below when the amending legislation is codified.
Notes to User
The McHenry County Stormwater Management Ordinance (this Ordinance) regulates development and substantial improvements to buildings in the floodplain throughout McHenry County, within incorporated and unincorporated areas alike. As you read through this Ordinance, you will notice that certain terms are underlined and the Ordinance uses numerous acronyms. Underlined terms are defined in Appendix 12 and acronyms are defined in Appendix 13.
Not all development is regulated by this Ordinance, but development that is regulated requires a stormwater management permit before construction is allowed to commence. Some development is regulated because of its size, such as: development that hydrologically disturbs 5,000 square feet or more; development that hydrologically disturbs 50% or more of a parcel; and development that results in an additional 20,000 square feet of impervious area since the original effective date of this Ordinance. Other development is regulated because of its location, regardless of its size. Examples include development that is located partially or completely in a flood hazard area or wetland.
The basic steps used to determine whether a particular project requires a stormwater management permit are listed below. The Permitting Flow Charts in Appendix 1 provide additional guidance. If you have any questions about this Ordinance or its applicability to a specific project, please contact the McHenry County Department of Planning and Development.
   1.   Determine whether your project meets the definition of development (see Appendix 12). If it does, go on to Step 2.
   2.   Determine whether your project is regulated development (see § 17.04.020B.). If it is, go on to Step 3.
   3.   Determine whether your project is exempted development (see § 17.04.020C.). If it is not, go on to Step 4.
   4.   Determine whether your project qualifies for a General Permit, which waives certain requirements of this Ordinance in order to streamline the permit process for specific types of routine projects (see § 17.04.030). If it does, follow the process described for that General Permit. If it does not, go on to Step 5.
   5.   Determine how your project is classified (see § 17.04.040A.) and then go on to Step 6.
   6.   Determine which Application Requirements apply (see § 17.04.050). Then go on to Step 7.
   7.   Determine which Performance Standards apply (see § 17.04.060). Then go on to Step 8.
   8.   Submit a complete stormwater management permit application to a Certified Community or to the McHenry County Department of Planning and Development, along with the required submittals.
   9.   Await the issuance of a stormwater management permit prior to commencing your project.
Section
Article I
   17.04.010   Introduction, authority and purpose
Article II
   17.04.020   Scope of regulation
Article III
   17.04.030   General permits
Article IV
   17.04.040   Stormwater management permit provisions
Article V
   17.04.050   Application requirements
Article VI
   17.04.060   Performance standards
Article VII
   17.04.070   Variances and appeals
Article VIII
   17.04.080   Inspections and access
Article IX
   17.04.090   Violation and penalty
Article X
   17.04.100   Procedure and enforcement
Article XI
   17.04.110   Disclaimer of liability
Article XII
   17.04.120   Severability
Article XIII
   17.04.130   Abrogation and greater restrictions
Article XIV
   17.04.140   Amendments
Appendices
   17.04.150   Appendix 1: Permitting Flowcharts
   17.04.160   Appendix 2: Standard Soil Erosion and Sediment Control Notes
   17.04.170   Appendix 3: Standard Drain Tile Notes
   17.04.180   Appendix 4: Rainfall Depth-Duration Frequency Tables for McHenry County
   17.04.190   Appendix 5: Hydrologic and Hydraulic Models and Techniques Approved by MCSC
   17.04.200   Appendix 6: Detention Volume vs. Percent Impervious Chart for McHenry County
   17.04.210   Appendix 7: IDNR/OWR Dam Safety Permit Flowchart
   17.04.220   Appendix 8: Public Bodies of Water in McHenry County
   17.04.230   Appendix 9: McHenry County Watersheds
   17.04.240   Appendix 10: McHenry County Watershed Plans
   17.04.250   Appendix 11: Floodplain and Floodway Maps
   17.04.260   Appendix 12: Definitions
   17.04.270   Appendix 13: Acronyms